This invention relates generally to a door system, and in particular, to a door system suitable for use for high temperature applications such as boilers, flues, bag houses, precipitators, scrubbers, and the like.
To gain access to compartments inside of boilers or other high temperature-type structures for inspection, repair, maintenance, such structures usually includes one or more access openings with doors. One such door is disclosed in U.S. Pat. No. 5,158,043, issued to Jon Emsbo, entitled “High Temperature Application Door Installation.” This door is configured for a gas-tight sealing engagement with an access opening in a high temperature environment, and includes an outer door panel, and an inner door assembly with an inner door plate having one or more transversely extending yokes mounted thereon.
Each yoke is pivotally attached at one end from one side of the door frame by hinges, and cooperates with a latch pin locking arrangement at the opposite end, which is used to maintain the door in a closed position. A handle is provided which, upon being turned, forces the inner door plate and yoke apart, and this reaction between the yoke and its associated mounting hinges and latch pin causes the inner door plate, which includes a peripherally-mounted sealing gasket, to be pressed firmly into engagement with the door frame, thereby sealing the door opening.
U.S. Pat. Nos. 4,574,973 and 4,685,586, both issued to Lewis, et al., also disclose doors for high temperature applications.